1. Field of the Invention
The present invention relates to a support preferably used for a thermal transfer image-recording material. The present invention also relates to a thermal transfer image-recording material which is excellent in glossiness, low in surface roughness and capable of producing a clear image. The present invention further relates to a thermal transfer image-recording material capable of sensitively producing an image with a high color density even at a lower thermal energy during printing.
Image production based on thermal transfer recording is generally effected by heating an ink ribbon containing a color material layer and a base supporting thereof, subliming or vaporizing dye included in such color material layer, and allowing such liberated dye to be fixed into a thermal transfer image-recording material.
More specifically as shown in FIG. 1, an ink ribbon 1 composed of a color material layer 5 which contains a sublimable or vaporizable dye and a base 4 supporting thereof is press-contacted with a thermal transfer image-recording recording material 2 composed of a thermal transfer image-recording layer 6 and a support 7 supporting thereof, between a drum 12 and a heat source 3 (thermal head, for example) which is controllable with electric signals, in which the color material layer 5 is heated by the heat source 3 to thereby allow the dye contained therein to sublime or vaporize and then to be fixed into the thermal transfer image-recording layer 6 of the thermal transfer image-recording material 2, which leads to the image production based on thermal transfer recording.
The support 7 of the thermal transfer image-recording material 2 is generally composed of pulp paper; opaque synthetic paper containing a stretched propylene-base resin film containing an inorganic fine powder (as disclosed in Examined Japanese Patent Publication 46-40794); or synthetic coated paper composed of a transparent polyethylene terephthalate film or transparent polyolefin-base resin film with an improved whiteness and dye fixing property attained by coating thereon an inorganic fine powder such as silica or calcium carbonate together with a binder.
Among these, a synthetic paper obtained by stretching a polyolefin resin film containing inorganic fine powder is acceptable since such paper having a lot of internal micro-voids is excellent in strength, dimensional stability, contact property with a printing head, copying property after thermal transfer printing, writing property with a pencil and in storability (as disclosed in Laid-Open Japanese Patent Publications Nos. 60-245593, 61-112693 and 63-193836). Such types of synthetic paper are stretched at a temperature lower than the melting point of the polyolefin-base resin to thereby form the internal micro-voids, in order to achieve desirable softness, opacity, contact property with a printing head, and paper feed/discharge property. While such synthetic paper has a number of excellent properties, recent trends need a thermal transfer image-recording material capable of producing an image with a higher glossiness. In particular, most preferable is capability in producing a high-density image even under high-speed printing conditions.
One proposal for increasing the glossiness relates to a synthetic paper having on the surface of a support a film layer substantially containing no inorganic filler. This synthetic paper, however, still suffers from degraded glossiness of image obtained by thermal transfer printing since the support has a surface roughness due to subtle external waviness.
In an attempt to address this problem, a thermal transfer image-recording material having less surface roughness enough for providing a clear image has also been provided (Laid-Open Japanese Patent Publication 7-179078).
However, more recently thermal transfer image-recording materials having a still higher level of surface glossiness have been required. Thus, there is a strong need for a practical thermal transfer image-recording material on which the user can visually recognize a high glossiness.
Accordingly, it is an object of the present invention to provide a thermal transfer image-recording material having a reduced surface roughness due to external waviness with very high glossiness. In particular, the present invention provides a practical thermal transfer image-recording material on which the user can visually recognize a high glossiness.
It is still another object of the present invention to provide a support containing such a thermal transfer image-recording material.
The above objects and others are provided by a support, containing:
a) a base layer (B) containing a biaxially stretched film of a thermoplastic resin containing an inorganic fine powder; and
b) a surface layer (A) provided at least on one side of the base layer (B), which is composed of a biaxially stretched film of a thermoplastic resin having a three-dimensional center plane average roughness of 0.3 xcexcm or below and a 60 degrees surface glossiness of 80% or above.